Make sure to add default display before others

Some parts of WM init assume that display with id 0 will be added
before all other displays. This CL traverses the displays from DM
from the beginning of the list, which will provide increasing
display ids.

Bug: 74446287
Test: Boot bat_land with 2 displays attached
Change-Id: Ie46954cc9f20a29f30c5f45fb6aabf46eba63fa8